[funkyhog]

Hello funkyhog

I have the ST3 and almost exactly your way to work (42km there and back) and most of it flat. I can walk a path with the ST3 in around 28 minutes.
On average, I reach around 43 to 44 km / h, but I also accelerate and don't dawdle.
I have the ST3 with a large 983Wh battery, I come home with around 45% of the remaining battery. I'm around 95 kilos, which certainly needs a bit more battery.
So the 814 Wh battery would easily suffice for your commute, but would recommend the large battery, because you will surely plan a tour otherwise and when the battery has a few years under its belt, the capacity will decrease.
I am very happy with the ST3.
I wish you much fun

Vielen Dank!